Programming learning record -- recursively solving the tower of Hanoi problem

1. The understanding of recursion , Pass and return , First, we need to design a benchmark situation , This benchmark case , In some cases , It can solve without recursion .
2. Then the problems encountered can be decomposed into benchmark cases , And non benchmark cases , Non benchmark cases can also be decomposed into benchmark cases and non benchmark cases .
3. Such as the tower of Hanoi , Suppose the number of discs is 4, Then the top three discs can be regarded as a whole , Form four discs with the lowest disc , The benchmark case is how to move when there is only one disk .4 The order is decomposed into 3 Step sum 1 rank ,3 The order is decomposed into 2 Step sum 1 rank ,2 Decompose into 1 Step sum 1 rank .
4. in fact , In the case of the tower of Hanoi ,1 The movement of the order can be seen as from A The column moves directly to C column
5. And in the second order , First step A First move to B, The second step A Then move to C, The third step B Move to C.
6. We know , When the first order A Move directly to C, therefore , We can regard the first three steps as non benchmark , The second step is to look at the benchmark situation .
7. First step , Can be seen as A It's the starting post ,C For the middle post ,B Is the first-order case of the target column , Third parts , It can be seen as B Is the starting column ,A It's the middle column ,C Is the first-order case of the target column .
8. So the second-order movement can be divided into three steps ,
1. saucer A<C>B First order movement of .2. Large disc A Move to C.3. saucer B<A>C First order movement of .
In the third order, the top two discs are regarded as a whole , The bottom disc is the reference case , The fourth order regards the top three as a whole ........

void move(char A, char C)
{
	printf("%c Column top disc moves to %c column \n", A, C);
}
void HNT(char A, char B, char C,int n)
{
	if (n == 1) move(A, C);
	else
	{
		HNT(A, C, B, n - 1);
			move(A, C);
		HNT(B, A, C, n - 1);
	}
}
int main()
{
	char A = 'a';char B = 'b';char C = 'c';//A Starting column ,B Transfer column ,C Target column 
	int x = 4;// Number of discs 
	HNT(A, B, C, x);
	return 0;
}